1. Field of the Invention
This invention relates generally to a wire bale binding machine that uses a control system incorporating memory, sensors and programmable logic controllers.
2. Related Art
Wire baling of bulk materials benefits from increased speed and reduced materials cost through automation. Bulk materials include fibrous bulk materials such as cotton and nylon. Fibrous materials are commonly formed into bales by simultaneous compression and binding. There is a continuing need in the automated baling art to improve the efficiency, reliability and accuracy of the bale binding process.
Baling wire performance requirements vary depending upon the bulk material being baled. Such requirements range from industry standard specifications to general operational parameters, such as minimum speeds required for profitability. The Cotton Council issues standards specifying particular lengths of wire around various sizes of bales and the tension that the wires must withstand. These standards vary for different bale configurations such as a “standard density” bale or “universal density” bale. The most common bale configuration is “standard density,” which is 20×54 inches in size, for which Cotton Council Industry Standards require six baling wires which are 9¼ inches apart from one another.
Current automated baling machines use an articulated track to guide wire around bales of bulk material, such as cotton, while that bale is under compression. Part of the wire guide track in current automated balers must be removable to a second position after the ends of the baling wire have been tied together, in order to allow ejection of the bale and insertion into the baler of the next unit of material for baling. Material to be baled is typically introduced into the automatic baler under vertical compression. Typical pressures for an industry standard 500 pound, 20×54 inch bale are in excess of 300 tons. Horizontal plates called follower blocks apply compression through platens which contact the surface of the cotton or other material being compressed. The Platens incorporate slots which run lateral to the longitudinal axis of the bale. There are six slots in the platens to allow six baling wires to be wrapped around the bale while it is still under compression. The lateral slots have lateral channels behind them for insertion of wire guide tracks in both the upper and lower platens in automatic balers.
Current automated baling machines operate with a certain degree of inefficiency. In order to loop baling wire around bulk material to be baled, release it from a guide track and knot the ends, tension must be generated on the wire. Likewise, in order to properly knot the ends of the wire, tension must be maintained in the twisting procedure that generates the knot. These tensions must be maintained within prescribed ranges to optimize efficiency and to produce a final bale compliant with industry standards. Certain knotting speeds must be avoided because too much speed in the twisting procedure produces metal fatigue. Too great a degree of tension overall can generate weaknesses or wear-points in the baling wire, or can generate wear in the wire guide tracks or other parts of the automated baling machine. Automated baling machines would benefit from more precise control of such variables. Currently, large margins of error for tension, torques and speeds must be built into the apparatus and method of using the apparatus in order to assure reliability of both the apparatus and the bulk material bales they produce. These wide margins of error manifest themselves in a variety of process difficulties, notably increased cycle time. Moreover, wide margins of error necessitate use of heavier gauge wire, which is more expensive.
There is a need in the art to increase the precision of controls in order to maximize speed while maintaining adequate compliance with industry standards, to maximize efficiency and reliability and in order to minimize wear and damage.